The shopping centre roars. Instead of tuning it out, I open my ears. It's closing time. The noise is made of individual sounds conglomerating — many loud voices, the clatter and clang of doors and bolts, the wind-rush of all the machinery that keeps this place functioning. That machinery wind-rush — also made up of different individual kinds of noise — is in the ceilings, the walls, and under the floors; it surrounds us.